Pole pruner with improved cutting head

ABSTRACT

A pole pruner having a cutting head of the single anvil type in which the cutting blade is formed of a relatively thin blade structure having an essentially single bevel construction with a non-symmetrical straight cutting edge, the cutting blade being arranged with respect to the fixed anvil member shape and location so that the free end of the cutting blade is slidably supported by the fixed anvil member during the portion of the cutting stroke where binding and lateral flexure is most likely to occur.

United States Patent Robison et al.

[ 1 Sept. 17,1974

POLE PRUNER WITH IMPROVED CUTTING HEAD Inventors: James W. Robison,Belpre, Ohio; Harold O. Eads, Parkersburg, W. Va.

Assignee: McDonough C0., Parkersburg, W.

Filed: Aug. 20, 1973 Appl. No.: 389,548

US. Cl. 30/249, 30/166 Int. Cl B26b 13/06, B26b 13/22 Field of Search30/166, 231, 244, 245,

References Cited UNITED STATES PATENTS 5/1912 Higley 5/1923 Barrett2/1970 Ballard 30/244 X 3,715,805 2/1973 Fraser 30/166 FOREIGN PATENTSOR APPLICATIONS 1,065,804 4/1967 Great Britain 30/246 Primary ExaminerAlLawrence Smith Assistant Examiner.l. C. Peters Attorney, Agent, orFirmCushman, Darby & Cushman [5 7 ABSTRACT A pole pruner having acutting head of the single anvil type in which the cutting blade isformed of a relatively thin blade structure having an essentially singlebevel construction with a non-symmetrical straight cutting edge, thecutting blade being arranged with respect to the fixed anvil membershape and location so that the free end of the cutting blade is slidablysupported by the fixed anvil member during the portion of the cuttingstroke where binding and lateral flexure is most likely to occur.

15 Claims, 9 Drawing Figures PAIENIEBsEr .1 mu

Sam 2m 3 POLE PRUNER WITH IMPROVED CUTTING HEAD This invention relatesto pole pruners and more particularly to improvements in pole prunerswhich render the same capable of cutting with greater efficiency andless bending action.

Pole pruners have been known for many years. In general, a pole prunerincludes an elongated handle, a cutting head assembly on one end of thehandle which includes a fixed member operable to be engaged with a limbor the like and a movable member operable to be moved through a cuttingstroke with relation to the limb engaged by the fixed member. Polepruners usually include a rope and pulley assembly which is operativelyconnected with the movable member and extends to the opposite endportion of the handle for effecting movement of the movable memberthrough its cutting stroke in response to a manually efiected pull and aspring assembly, usually connected between the fixed and movable membersof the cutting head assembly, for effecting a movement of the movablemember through a return stroke.

The biggest problem presented in the operation of pole pruners of thetype noted above occurs when the operator attempts to use the polepruner to cut a limb of a size which is close to the maximum size withinthe operative range of the tool. The problem presented is not so much acutting problem as it is a binding problem in that the capability ofeffecting a cutting action is clearly present, but in the attempt toachieve the capability, the cutting action is prevented due to thebinding of the cutting blade within the limb which is to be cut. Thisbinding problem is particularly aggravating when it is considered thatthe cutting action takes place at the end of a handle with a length ofas much as l2 feet which is often held by the operator over his head.Once the binding action occurs, it becomes extremely difficult for theoperator to release the cutting blade since the only force tending toeffect release is provided by the spring. Severe damage to the devicecan be inflicted when the operator attempts to extricate the tool from asituation of this type.

Many of the pole pruners currently available commercially utilize as apart of the movable member a relatively thin cutting blade having asymmetrical double beveled cutting edge disposed in the center of theblade thickness. The fixed member utilized with double beveled cuttingblades is invariably of a split anvil construction providing two spacedrigid portions which engage the limb in opposed relation to thedirection of cut on opposite sides of the plane of the cutting edge.When it is considered that the normal direction of the cutting blade isupwardly in relation to the limb so that the weight of the limb tends toprovide a binding force as the cutting action proceeds, it can befurther appreciated that the application of downward forces on oppositesides of the cutting plane by the split anvil tends to materially add tothe binding action present in a manner which increases in response toincreases in the actuating pull force. Over the years, there have beenmany proposed solutions to the binding problems presented by theconventional double beveled cutting edgesplit anvil cutting heads. Forexample, it has been proposed to mount the cutting blade so that it cutsdownwardly so as to utilize the weight of the limb being cut toalleviate binding (see US. Pat. No. 988,153), but

2 this proposal has not been adopted commercially .as the solution.

Of course, the binding problem canbe eliminated by limiting the maximumcapacity of the tool. But this solution merely results in the necessityof the operator to pay the additional costs of a more expensive too].One such tool currently available commercially utilizes two cast ironmembers of relatively thick size which are precision ground to provide acurved cutting edge on the fixed limb engaging member and a curvedsingle bevel cutting blade on the movable member. The relationshipbetween these two cutting edges is such that when the operator attempts.to cut a limb which is of a size slightly greater than that which canbe received within the fixed member, the curvature ,of the cutting bladetends to move the limb out of the path of movement of the blade awayfrom engaged relation to the fixed member. When a cutting action isachieved within the maximum limb size, the arrangement, due to theelimination .of the aforesaid binding forces provided by a split anvilconstruction, does not tend to bind in the same manner as statedpreviously. The binding forces imposed on a single bevel-single anvilarrangement while eliminating the inherent binding action of the doublebevel-split anvil arrangement, nevertheless presents an inherentlydifferent problem which is related to binding. Thus, when a single bevelnonsymmetrical cutting blade is moved through a maximum size limb, thereis imposed upon the blade binding forces having a lateral resultantcomponent which tends to bend the blade. Once the blade is bent beyondits elastic limit, the situation can only get worse because theunbalanced lateral component increases with increased flexure. Topreclude this action, the blade member of the prior art cutting head ismade of cast iron of a thickness to resist flexure beyond the elasticlimit of the material. A point of diminishing return is rapidlyencountered however, since increasing the blade thickness increases thebinding forces imposed thereon. Moreover, as previously indicated, aconstruction of this type is quite costly because of the precisiongrinding which must be performed.

An object of the present invention is to provide a pole pruner whichachieves the advantages of known single bevel-single anvil arrangementsin terms vof the elimination of the binding tendencies inherent in theknown double bevel-split anvil arrangements, while still obtaining theeconomical advantages of the latter which heretofore have not beenachieved in the known single bevel-single anvil arrangements. Inaccordance with the principles of the present invention, this objectiveis obtained by utilizing arelatively thin blade member of a constructionsimilar to that heretofore utilized in the symmetrical double bevelarrangements but having an essentially single bevel arrangement with anonsymmetrical straight cutting edge. By then relating the shape andlocation of the cutting blade with the shape and location of the freeend portion of the fixed member so that the free end of the cuttingblade is slidably supported by the fixed member during the portion ofthe cutting stroke where binding or lateral flexure is most likely tooccur, both binding and flexure are substantially eliminated. The addedresistance to the cutting movement occasioned by the aforesaid slidingaction can be reduced to a negligible factor by suitable antifrictionmaterial such as conventional lubrication or, more conveniently, byproviding the cutting blade with a Teflon coating. To insure properoperation, the fixed member is provided with a cam surface at theposition of initial overlap during the cutting stroke which merges intothe planar sliding surface thereof.

Another object of the present invention is the provision of an improvedcombined rope guide and handle part clamping assembly in a pole prunerof the type embodying a telescopic handle assembly which provides forincreased effectiveness both in the telescopic adjustment of the handleassembly and in the operation of the rope and pulley assembly foractuating the cutting head.

Still another object of the present invention is the provision of a polepruner of the type described which is simple in construction, efficientand durable in operation, and economical to manufacture.

These and other objects of the present invention will become moreapparent during the course of the following detailed description andappended claims.

The invention may best be understood with reference to the accompanyingdrawings wherein illustrative embodiments are shown.

IN THE DRAWINGS:

FIG. 1 is a side elevational view of a pole pruner embodying theprinciples of the present invention;

FIG. 2 is an enlarged fragmentary elevational view of the cutting headassembly of the pole pruner shown in FIG. 1, the movable member beingshown in full lines in an intermediate position of movement through itscutting stroke and in phantom lines in a position at the completion ofits cutting stroke;

FIG. 3 is a front elevational view of the stroke shown in FIG. 2;

FIG. 4 is a fragmentary sectional view taken along the line 44 of FIG.2;

FIG. 5 is an enlarged fragmentary sectional view taken along the line5-5 of FIG. 1;

. FIG. 6 is an enlarged'sectional view taken along the line 6-6 of FIG.1;

FIG. 7 is a view similar to FIG. 1 illustrating a modified form of thehandle construction of the pole pruner;

FIG. 8 is an enlarged fragmentary sectional view taken along the line 88of FIG. 7; and

FIG. 9 is an enlarged sectional view taken along the line 99 of FIG. 7.

Referring now more particularly to FIG. 1 of the drawings, there isshown therein a pole pruner, generally indicated at 10, which embodiesthe principles of the present invention. The pole pruner 10 includes, ingeneral, an elongated handle assembly, generally indicated at 12, which,as shown, is preferably of the telescopically adjustable type, a cuttinghead assembly, generally indicated at 14, on one end of the handleconstruction, a pruning saw 16 carried by the cutting head 14 and a ropeand pulley assembly, generally indicated at 18, operatively connectedwith the cutting head and extending to the opposite end portion of thehandle assembly for actuating the cutting head in response to a manuallyeffected pull.

The cutting head assembly 14 consists essentially of a fixed member,generally indicated at 20, operable to be engaged with a tree limb orthe like, a movable member, generally indicated at 22, operable to bemoved through a cutting stroke with relation to the limb engaged by thefixed member 20 and the movable member 22 for effecting movement of thelatter through a return stroke.

Referring now more particularly to FIGS. 2 and 3, the fixed member 20 ispreferably in the form of a rigid metallic member, the specificallypreferred form shown being punched from steel plate stock. As shown, theshape of the member is such as to include an end portion 26 adapted tobe fixedly connected with one end of the handle construction, a fixedintermediate portion 28 extending generally longitudinally outwardly ofthe aforesaid end of the handle, a second intermediate portion 30extending transversely from the first intermediate portion 28 and a freeend portion 32 extending transversely inwardly from the secondintermediate portion in spaced relation from the first intermediateportion 28.

The first intermediate portion 28 includes a straight limb engagingsurface 34 which faces in a direction toward the free end portion 32 andthe latter includes a limb engaging surface 36 which faces toward thefirst intermediate portion 28. Formed in the second intermediate portion30 is a limb engaging surface 38 which extends between and interconnectsthe limb engaging surfaces 34 and 36. In the preferred embodiment shown,the limb engaging surface 38 is of arcuate configuration about a singleaxis which is tangential at one end to the straight surface 34. The limbengaging surface 36 of the free end portion 32, as shown, is generallystraight and likewise is tangential to the opposite end of the surface38. The straight surface 36 diverges in a direction toward the outerextremity of the free end portion 34 with relation to the straightsurface 34 at an angle which is approximately 16.

It will also be noted that with the preferred embodiment shown whereinthe fixed member 20 is formed of flat plate stock, the fixed memberprovides a common planar surface to all of the aforesaid portionsthereof which intersects with the limb engaging surfaces 34, 36 and 38.It will also be noted that the fixed member 20, as shown, is preferablyprovided with a branch hook portion 40 extending from the firstintermediate portion 28 in opposed relation to the limb engaging surface34 thereof. It will be understood that the provision of the branch hook,while preferable, is an optional feature. Similarly, the provision of apruning saw 16, while preferred, is likewise an optional feature. Inthis regard, it will be noted that the pruning saw provided is of aconcavely curved type provided with cutting teeth of approximately fiveper inch. The pruning saw can be detachably fixedly secured to the fixedmember 20 by any suitable means and, as shown, such means takes the formof an attaching pin 42 fixedly engaged to the second intermediateportion 30 and extending therefrom perpendicular to the aforesaid planarsurface thereof for engagement within the base of the saw blade. Thebase of the saw blade includes a parallel opening which is adapted toregister with an opening in the second intermediate portion 30 of thefixed member 20 for the purpose of receiving therethrough conventionalfastening means 44, such as a bolt and wing nut assembly or thelike. Asshown in FIG. 1, the base of the saw blade may be provided with a secondfastener receiving opening for the purpose of providing angularadjustability of the position of the saw blade.

The movable member 22 is also preferably in the form of a rigid metallicmember, the specific embodiment shown again being punched from platesteel stock and suitably heat treated. As shown, the movable memberincludes a cutting blade portion 46 and a lever arm portion 48. Inaccordance with the preferred construction as stated above, the movablemember thus provides a planar surface which, when the movable member ismounted in operative relation with the fixed member, is disposed incoincidental relation with the aforesaid common planar surface of thefixed member 20. As shown, the movable member is mounted on the fixedmember, as by a pivot bolt assembly 50, for pivotal movement between twolimiting positions about an axis extending perpendicular to theaforesaid coincident planar surfaces which is disposed adjacent thejuncture between the first and second intermediate portions of the fixedmember and the juncture between the cutting blade and lever arm portionsof the movable member 22.

The blade portion 46 has formed thereon a straight cutting edge 52,which substantially intersects the aforesaid planar surface thereof. Asbest shown in FIG. 4, the cutting edge is defined by a straight bevelconfiguration which includes first relatively narrow straight doublebevel surfaces 54 which intersect with the cutting edge 52 and extendtherefrom at an angle of approximately 45 with respect to a'flat planeintersecting the cutting edge parallel to the planar surface of theblade portion 46 and a second relatively wide straight bevel surface 56which intersects with one side of the double bevel surface 54 andextends to the opposite surface of the blade portion at an angle ofapproximately 6-% with respect to the planar surface intersecting thecutting edge 52.

The straight bevel surface construction described above is from afunctional standpoint a single bevel arrangement, despite the provisionof the double bevel surfaces 54, since the construction is such thatwhen the blade is moved through a limb or the like, the resultantlateral forces are imbalanced rather than balanced as in a double bevelarrangement. The construction can be considered a single bevelarrangement from a structural standpoint in that the cutting edge is notsymmetrical with respect to the blade thickness. While the presentinvention clearly contemplates a construction in which the cutting edge52 is defined by only a single first bevel surface 54 which extends allthe way to the planar surface of the blade portion 46, the double bevelsurfaces 54, as shown and described, are preferred because the resultantcutting edge is stronger and less subject to damage by engagement withthe fixed member 20 due to lateral bending during operation because ofthe slight lateral offset between the cutting edge and the planarsurface of the blade portion 46. Moreover, the present arrangementreduces the resultant lateral forces somewhat.

The movable member 22 is limited in its pivotal movement about the axisprovided by the bolt assembly 50 between the aforesaid two limitingpositions by any suitable means, such as a stop pin 58 extending fromthe lever arm portion 48 beyond the aforesaid planar surface thereof ina position to engage the rear surface of the second intermediate portionwhen in the limiting position into which it is urged by the spring 24and to engage the rear surface of the first intermediate portionadjacent the hook portion when in the other limiting position.

During the movement of the movable member 22 from its spring urgedlimiting position to its other limiting position, the cutting bladeportion 46 is moved through a cutting stroke. The location of the pivotpin 50 in relation to the fixed member 20 and movable member 22 ischosen so that at the beginning of the cutting stroke, the straightcutting edge 52 is disposed in substantial alignment with the straightlimb engaging surface 34 of the first intermediate portion 34, as shownin FIG. 1, and, at the end of the cutting stroke the cutting edge 52 isdisposed substantially at right angles to the surface 34 and in generalalignment with the outermost portion of the limb engaging surface 38 ofthe second intermediate portion 30, as shown in broken lines in FIG. 2.

The location of the pivot pin 50 is so related to the longitudinalextent of the cutting blade portion 46 from the pivotal axis and thelongitudinal extent of the free end portion 32 from the secondintermediate portion that the outer extremity of the cutting bladeportion 46 overlaps the outer extremity of the free end portion 32 whenthe cutting edge 52 reaches an angular position of approximately 45 withrespect to the surface 34 during the cutting stroke, as shown in fulllines in FIG. 2. As best shown in FIGS. 3 and 4, the outer extremity ofthe free end portion is provided with a cam surface 60 which merges withthe planar surface thereof. As shown, the cam surface 60 is preferablyprovided by simply bending the outer extremity of the free end portionin a direction away from the cooperating planar surface of the cuttingblade.

Referring now more particularly to FIGS. 1, 5 and 6, the handle assembly12 includes a pair of handle parts 62 and 64 which, in the embodimentshown in FIG. 1, are arranged to be mounted in telescopic relation withrespect to one another. The handle parts may be of any suitableconstruction and, as shown,.are of cylindrical tubular configurationmade of aluminum. The cutting head 14 is secured to the end portion ofthe handle part 62 which extends outwardly from the handle part 64.While any suitable means may be utilized for effecting the connectionbetween the handle part 62 and the fixed member 20 of the cutting head14, as shown, the end portion of the handle part 62 is appropriatelyreenforced, as by a wooden core element 66, which is mounted within theend portion of the handle part 62 filling the interior thereof. A kerf68 is formed in the outer end portion of the handle part 62 and coreelement 66 within which the end portion 26 of the fixed member 20 of thecutting head 14 is engaged. The end portion 26, handle part 62 and coreelement 66 are provided with registering openings extending therethroughin a direction transverse to the kerf 68 for receiving appropriatefastening elements, such as bolt assemblies 70 or the like.

The handle assembly 12 also includes means for fixedly securing the twohandle parts 62 and 64 to gether in any desired position of telescopicadjustment which, as shown, is in the form of a combined clamp and ropeguide assembly, generally indicated at 72, embodying the principles ofthe present invention. The preferred embodiment shown includes a pair ofrigid metal plates each similarly shaped to provide a pair oflongitudinally spaced generally semi-cylindrically configured portions74 for embracing the handle parts adjacent their juncture, a fastenerreceiving tab 76 extending from one end of each semi-cylindrical portion74, and an integral flat portion 78 extending from the opposite ends ofthe semi-cylindrical portions 74. The

flat portions 78 are interconnected in spaced relation by a series offasteners 80, preferably in the form of shouldered rivets extendingthrough one of the flat portions 78 and fixed to the other. As shown,two rivets are provided adjacent the semi-cylindrical portions 74 and athird rivet is disposed outwardly therefrom and has a pulley 82journaled thereon between the associated plate portions78.

The two lower semi-cylindrical portions 74 are disposed in embracingrelation to the end of the handle part 64 from which the handle part 62extends and are detachably fixedly secured thereon by a suitablefastening element extending through the associated tabs 76 thereof. Thetwo upper semi-cylindrical portions 74 are disposed in embracingrelation to a split sleeve 84 slidably engaged on the exterior of thehandle part 62. The split sleeve 82 is preferably made of nylon or thelike and has one end thereof disposed in engagement with the adjacentend of the handle part 64. The sleeve is retained against longitudinalmovement in a direction away from the handle part 64 by means of anexterior radial flange 86 extending between each pair of spacedcylindrical portions. In order to prevent rotation of the split sleeve84, the latter may be provided with an enlarged portion adapted to bedisposed between the plate portions 78. It will be understood that theupper two semi-cylindrical portions 74 are thus adapted to permitrelative longitudinal telescopic movement of the handle part 62 withrespect to the handle part 64. In order to fixedly secure the handleparts 62 and 64 in any position of telescopic adjustment, an appropriatefastener assembly 88 is provided between the associated tabs 76 foreffecting the clamping action. As shown, the fastener assembly includesan eye-bolt having a nut threaded on the shank thereof. The shankextends through registering openings in the associated tabs, the openingopposite from the nut being of square configuration. A second nut isthreadedly engaged on the outwardly extending end of the shank and has akeeper clip engaged thereon which has tabs thereon extending through thesquare opening to prevent rotation of the nut. With this type ofassembly, the clamping action of the assembly 72 is achieved by turningthe eyebolt of the assembly 88 in a direction to tighten the assembly.

As previously indicated, the pulley 82 of the assembly 72 provides arope guiding function and thus forms part of the rope and pulleyassembly 18. In the preferred embodiment shown, the rope and pulleyassembly 18 embodies a single pulley arrangement although it will beunderstood that a plural pulley arrangement may be utilized if desired.The single pulley arrangement is preferred since it provides an optimumbalance between mechanical advantage, efficiency and the linear extentof the pull required to accomplish movement of the blade portion throughits cutting stroke.

The specific arrangement of the rope and pulley assembly 18 includes anelongated rope 90 having one end thereof knotted, as indicated at 92.From the knot 92, the rope extends through an opening 94 formed in thehandle part 62 and core element 66 at a position spaced below the endportion 26 of the cutting head 14. From the opening 94, the rope 90extends around a pulley assembly, generally indicated at 96, and thenbetween the inner periphery of the guide roller 82 and the adjacentrivets 80. The opposite end portion of the rope 90 extends through atransversely apertured pull handle 98 and is knotted at a position,depending upon the position of the telescopic adjustment of the handleparts 82 and 84, of convenient access to the operator.

It will be noted that the operation of the clamping assembly 72 is suchthat during the telescopic extension of the handle part 82 with respectto the handle part 84, no positive means is provided for preventing thehandle part 82 from being moved completely out of the part 84. In orderto permit the operator to conveniently effect full extension without theinconvenience of removal, the exterior surface of the inner end portionof the handle part 82 is provided with suitable visual indicia, such asa colored coating or the like, which will provide the operator with avisual indication that full extension has been effected. In addition, asshown in FIG. 1, rope 90 has a knot 102 tied therein in a position toengage the guide pulley 82 when the handle part 62 reaches fullextension, providing the operator with a further indicia of fullextension which can be felt, by virtue of the fact that furtherextension will effect movement of the cutting head against the action ofspring 24.

It will be noted that pulley assembly 96 includes the usual pulley,which like the guide pulley 82 is preferably made of nylon or the like,journaled in a riveted frame structure. As shown, the frame structure ispreferably pivoted, as by a pivot pin 104, to the free end of the leverarm portion 48 so as to permit the same to be moved from the normaloperative position in a counterclockwise direction as viewed in FIG. 1into a packaging position. This capability materially reduces the sizeand cost of packaging and shipping the present pole pruner 10. A stoppin 106 is provided on the riveted frame of the assembly 96 forretaining the same in its operative position by engagement thereof withthe adjacent edge of the lever arm portion 48. It will be noted that thetension of the rope 90 will maintain the stop pin 106 in such engagementthroughout the movement of the movable member 20 between its twolimiting positions.

The above described construction of the pole pruner 10 is preferred whenthe handle assembly 12 thereof provides for telescopic adjustment. Itwill be understood, however, that the aforesaid principles of thecutting head 14 of the present invention may be utilized with othertypes of handle assemblies including a onepiece handle assembly, ifdesired. FIGS. 7-9 illustrate the cooperation of the cutting head 14with a two-piece handle assembly 12' which is of generally conventionalconstruction. As shown, the handle assembly 12' includes a pair ofhandle parts 108 and 110 made of wood in conventional fashion. In thisembodiment, the end portion 26 of the cutting head 14 is detachablyfixedly connected to one end of the handle part 108 which is formed witha kerf 112 to receive the same. The connection is reinforced by a pairof generally semi-cylindrically shaped metal plate members 114 mountedon the exterior of the handle part 108 on opposite sides of the kerf112. As before, the reinforcing members, handle part and end portion aresuitably apertured to receive therethrough appropriate fasteners, suchas bolt assemblies 116. As before, the handle part 108 is apertured, asat 1 18, in spaced relation below the end portion 26 to receive thereinthe associated end portion of the rope 90.

The handle part 108 functions as a one-piece handle for pruning limbswhich can be reached by the operator by grasping the free end of thehandle part 108. For higher limbs, the handle part functions as a handleextension which can be detachably fixedly secured to the free end of thehandle part 108. Any suitable means may be utilized to effect thisconnection, the embodiment shown being generally of a conventionalnature. With particular reference to FIG. 9, the connecting meansincludes a pair of generally semicylindrically shaped outer metalclamping plates 120 and an inner split sleeve 122 also made of metal,preferably aluminum or the like, rather than steel as is preferred forthe plates 120.

In assembling the joint split sleeve 122 is centered over the adjacentlongitudinally aligned ends of the handle parts 108 and 110 and then theplates 120 are mounted in opposed surrounding relation to the splitsleeve. The end portions of the plates 120 extend beyond the ends of tesplit sleeve and are apertured to register with apertures formed in theend portions of the handle parts 108 and 110 respectively. The assemblyof the joint is completed by inserting and tightening a conventionalbolt assembly 124 through one of the sets of registering openings and aneye bolt assembly 126 through the other set. The eye of the boltassembly receives the rope 90 therethrough and serves a guiding functionsimilar to the guide roller 82 when the handle assembly 12 is in itsfully extended position as shown in FIG. 1.

This rope guiding function which is known in twopiece handle assembliesis considered to be particularly desirable because it serves to insurethat the pull forces on the rope will be transmitted to the handle partcarrying the cutting head with maximum compression and minimum bending.In the absence of the rope guide function, the operator tends to effectthe pull on the rope from a position spaced laterally from the handle,thus severely increasing the transmission of bending forces to thehandle. The severe transmission of bending forces to the handle inconjunction with the bending action heretofore mentioned in connectionwith known cutting heads have been the cause of injury to known polepruners, and perhaps, to operators as well, in the past.

The provision of the rope guiding function in telescopically adjustablehandle assembly by means of a combined rope guiding and telescopicadjustment securing assembly, such as described above and indicated at72, is, in accordance with the principles of the present invention, asignificant improvement in the telescopically adjustable handleassemblies heretofore known. In this case, the rope guiding function isretained throughout the entire extent of the telescopic adjustmentprovided insuring at all times against the transmission of severebending forces to the interior telescoping handle part which could causepermanent deformation of the type severely restricting, if notpreventing, the telescopic action.

This desirable safeguard is provided by a simple assembly which is ofeconomical construction and which additionally provides for theeffective securement of the two telescopically arranged handle parts inany desired position of adjustment. The rope guiding function doesdiminish somewhat the transmission of the maximum pull force to thecutting head which can be exerted by the operator on the rope (ascompared with the aforesaid pull without guidance from a laterally,outwardly spaced position) and hence the rope guiding function can betotally effective only when the cutting head is operable without theaforesaid binding action.

The cutting head 14 of the present invention cuts up to I-% inchdiameter limbs without binding with a cutting action which is from 40percent to 78 percent easier than known commercial pole pruners. Theseresults are achieved first because the basic cutting action is by acutting blade portion which has an essentially single bevel constructionor a nonsymmetrical cutting edge and which cooperates with a singlefixed member disposed on the flat side thereof, as distinguished fromdouble beveled cutting edges which cooperate with portions of the fixedmember spaced on both sides thereof. Moreover, this improved cuttingaction is achieved by minimizing the thickness of the cutting bladeportion and providing for the cam surface guided sliding support of theouter extremity of the cutting blade portion before the cutting actionin a limb of maximum size has proceeded to the point of creatingexcessive bending forces on the blade portion. The straight cutting edgeconfiguration is desirable not only because of its simplicity andeconomy, as compared with curved cutting edges, but because of itsparticular cooperation with the limb engaging surfaces. Thus, as thecutting action proceeds, the direction of cut approaches a directionwhich is almost aligned with the direction of the closed end of the limbengaging surfaces, thus insuring that the limb will be forced into theclosed end and be severed as the cutting stroke is completed.

It thus will be seen that the objects of this invention have been fullyand effectively accomplished. It will be realized, however, that theforegoing preferred specific embodiment has been shown and described forthe purpose of illustrating the functional and structural principles ofthis invention and is subject to change without departure from suchprinciples. Therefore, this invention includes all modificationsencompassed within the spirit and scope of the following claims.

What is claimed is:

1. In a pole pruner of the type including an elongated handle, a cuttinghead assembly on one end of said handle including a fixed memberoperable to be engaged with a limb or the like and a movable memberoperable to be moved through a cutting stroke with relation to the limbengaged by said fixed member, a rope and pulley assembly operativelyconnected with said movable member and extending to the opposite endportion of said handle for effecting movement of said movable memberthrough said cutting stroke in response to a manually effected pull, andspring means for effecting movement of said movable member through areturn stroke, the improvement in said cutting head assembly whichcomprises said fixed member being a rigid metallic member having an endportion fixedly connected with said one end of said handle, a firstintermediate portion extending generally longitudinally outwardly ofsaid one end of said handle, a second intermediate portion extendingtransversely from said first intermediate portion, and a free endportion extending transversely inwardly from said second intermediateportion in spaced relation to said first intermediate portion,

said first intermediate portion including a straight limb engagingsurface facing in a direction toward said free end portion, said freeend portion including a limb engaging surface facing toward said firstintermediate portion, said second intermediate portion having a limbengaging surface interconnecting the limb engaging surfaces of saidfirst intermediate portion and said free end portion,

said first and second intermediate portions and said free end portionhaving a common planar surface intersecting the limb engaging surfacesthereof,

said movable member being a rigid metallic member including a cuttingblade portion and a lever arm portion,

means for mounting said movable member on said fixed member for pivotalmovement between two limiting positions about an axis extendingperpendicular to the aforesaid common planar surface and disposedadjacent the juncture between said first and second intermediateportions and the juncture between said cutting blade and lever armportions,

said cutting blade portion having a planar surface disposed in aposition to slidably engage the common planar surface of said firstintermediate portion and said free end portion during said cuttingstroke, a straight cutting edge substantially intersecting the planarsurface thereof, and bevel surface means extending from said straightcutting edge,

said straight cutting edge being disposed in substantial alignment withthe straight limb engaging surface of said first intermediate portion atthe initiation of said cutting stroke and extending generally at rightangles thereto and in general alignment with the outermost portion ofthe limb engaging surface of said second intermediate portion at thecompletion of said cutting stroke,

the extent of said cutting blade portion from said pivotal axis being sorelated to the extent of said free end portion from said secondintermediate portion that the outer extremity of said blade portionoverlaps the outer extremity of said free end portion during the cuttingstroke of said cutting blade portion when said cutting edge has reachedan angular position of approximately 45 with respect to the straightlimb engaging surface of said first intermediate portion,

the outer extremity of said free end portion having a cam surfacethereon merging into the planar surface thereof.

2. The improvement as defined in claim 1 wherein said movable member andsaid fixed member are both formed from flat plate stock.

3. The improvement as defined in claim 2 wherein said cam surface isprovided by bending the outer extremity of said free end portion in adirection away from the planar surface of said cutting blade portion.

4. The improvement as defined in claim 3 wherein said bevel surfacemeans includes first straight double bevel surfaces, each extending fromsaid cutting edge at an angle of approximately 45 with respect to aplane intersecting said cutting edge and extending parallel to theplanar surface of said cutting blade portion and a second straight bevelsurface extending from one of said first bevel surfaces to the surfaceof said cutting blade portion opposite the planar surface thereof at anangle to the latter of approximately 6 5. The improvement as defined inclaim 4 wherein said cutting blade portion is coated with Teflon.

6. The improvement as defined in claim 5 wherein the entire exterior ofthe movable member is coated with Teflon.

7. The improvement as defined in claim 2 wherein the limb engagingsurface of said second intermediate portion is arcuate about a singleaxis and interconnects tangentially with the limb engaging surfaces ofsaid first intermediate portion and said free end portion.

8. The improvement as defined in claim 7 wherein the limb engagingsurface of said free end portion is straight and diverges toward theouter extremity thereof at an angle of approximately 16 with respect tothe limb engaging surface of said first intermediate portion.

9. Theimprovement as defined in claim 1 including a pruning saw andmeans for detachably fixedly securing said pruning saw to said secondintermediate portion in generally longitudinally outwardly extendingrelation therewith.

10. In a pole pruner of the type including an elongated telescopichandle assembly, a cutting head assembly on one end of said handleassembly including a fixed member operable to be engated with a limb orthe like and a movable member operable to be moved through a cuttingstroke with relation to the limb engaged by said fixed member, a ropeand pulley assembly operatively connected with said movable member andextending to the opposite end portion of said handle assembly foreffecting movement of said movable member through said cutting stroke inresponse to a manually effected pull, and spring means for effectingmovement of said movable member through a return stroke, the improvementin said telescopic handle assembly which comprises a first tubularhandle part, a second tubular handle part telescopically mounted withinsaid first handle part and extending outwardly from one end thereof, anda combined handle part securing and rope guiding assembly includingsecuring means fixedly secured to the exterior periphery of the one endof said first handle part and releasably fixedly connected with theexterior periphery of the portion of said second handle part extendingoutwardly thereof for releasably fixedly securing said second handlepart with respect to said first handle part in any desired position oftelescopic adjustment, and guiding means for receiving and guiding theportion of the rope of said rope and pulley assembly extending to theopposite end portion of said handle assembly.

11. The improvement as defined in claim 10, wherein said rope portion isformed with a knot at a position to engage said guide means when saidsecond handle part is moved into a fully extended position of telescopicadjustment with respect to said first handle part providing the operatorwith indicia of the relative telescopic position of said handle parts soas to prevent disengagement of said second handle part from said firsthandle part.

12. The improvement as defined in claim 11, wherein the exterior surfaceof said second handle part adjacent the portion extending from the oneend of said first handle part when said second handle part is in a fullyextended position of telescopic adjustment is provided with colorindicia.

13. The improvement as defined in claim 10, wherein said securing meansincludes a pair of cooperating clamping plates, each comprising a pairof longitudinally spaced generally semi-cylindrically shaped centralportions, fastener receiving tab portions extending from one end of eachcentral portion, and an integral portion extending from the oppositeends of said cen- "tral portions, means retaining said integral portionsin spaced relation on one side of said handle parts, first fastenermeans carried by one cooperating pair of fastener receiving tab portionsfor releasably fixedly securing the associated central portions infriction tight engagement to said exterior periphery of said firsthandle part, and second fastener means carried by the tween saidintegral portions.

1. In a pole pruner of the type including an elongated handle, a cuttinghead assembly on one end of said handle including a fixed memberoperable to be engaged with a limb or the like and a movable memberoperable to be moved through a cutting stroke with relation to the limbengaged by said fixed member, a rope and pulley assembly operativelyconnected with said movable member and extending to the opposite endportion of said handle for effecting movement of said movable memberthrough said cutting stroke in response to a manually effected pull, andspring means for effecting movement of said movable member through areturn stroke, the improvement in said cutting head assembly whichcomprises said fixed member being a rigid metallic member having an endportion fixedly connected with said one end of said handle, a firstintermediate portion extending generally longitudinally outwardly ofsaid one end of said handle, a second intermediate portion extendingtransversely from said first intermediate portion, and a free endportion extending transversely inwardly from said second intermediateportion in spaced relation to said first intermediate portion, saidfirst intermediate portion including a straight limb engaging surfacefacing in a direction toward said free end portion, said free endportion including a limb engaging surface facing toward said firstintermediate portion, said second intermediate portion having a limbengaging surface interconnecting the limb engaging surfaces of saidfirst intermediate portion and said free end portion, said first andsecond intermediate portioNs and said free end portion having a commonplanar surface intersecting the limb engaging surfaces thereof, saidmovable member being a rigid metallic member including a cutting bladeportion and a lever arm portion, means for mounting said movable memberon said fixed member for pivotal movement between two limiting positionsabout an axis extending perpendicular to the aforesaid common planarsurface and disposed adjacent the juncture between said first and secondintermediate portions and the juncture between said cutting blade andlever arm portions, said cutting blade portion having a planar surfacedisposed in a position to slidably engage the common planar surface ofsaid first intermediate portion and said free end portion during saidcutting stroke, a straight cutting edge substantially intersecting theplanar surface thereof, and bevel surface means extending from saidstraight cutting edge, said straight cutting edge being disposed insubstantial alignment with the straight limb engaging surface of saidfirst intermediate portion at the initiation of said cutting stroke andextending generally at right angles thereto and in general alignmentwith the outermost portion of the limb engaging surface of said secondintermediate portion at the completion of said cutting stroke, theextent of said cutting blade portion from said pivotal axis being sorelated to the extent of said free end portion from said secondintermediate portion that the outer extremity of said blade portionoverlaps the outer extremity of said free end portion during the cuttingstroke of said cutting blade portion when said cutting edge has reachedan angular position of approximately 45* with respect to the straightlimb engaging surface of said first intermediate portion, the outerextremity of said free end portion having a cam surface thereon merginginto the planar surface thereof.
 2. The improvement as defined in claim1 wherein said movable member and said fixed member are both formed fromflat plate stock.
 3. The improvement as defined in claim 2 wherein saidcam surface is provided by bending the outer extremity of said free endportion in a direction away from the planar surface of said cuttingblade portion.
 4. The improvement as defined in claim 3 wherein saidbevel surface means includes first straight double bevel surfaces, eachextending from said cutting edge at an angle of approximately 45* withrespect to a plane intersecting said cutting edge and extending parallelto the planar surface of said cutting blade portion and a secondstraight bevel surface extending from one of said first bevel surfacesto the surface of said cutting blade portion opposite the planar surfacethereof at an angle to the latter of approximately 6- 3/4 *.
 5. Theimprovement as defined in claim 4 wherein said cutting blade portion iscoated with Teflon.
 6. The improvement as defined in claim 5 wherein theentire exterior of the movable member is coated with Teflon.
 7. Theimprovement as defined in claim 2 wherein the limb engaging surface ofsaid second intermediate portion is arcuate about a single axis andinterconnects tangentially with the limb engaging surfaces of said firstintermediate portion and said free end portion.
 8. The improvement asdefined in claim 7 wherein the limb engaging surface of said free endportion is straight and diverges toward the outer extremity thereof atan angle of approximately 16* with respect to the limb engaging surfaceof said first intermediate portion.
 9. The improvement as defined inclaim 1 including a pruning saw and means for detachably fixedlysecuring said pruning saw to said second intermediate portion ingenerally longitudinally outwardly extending relation therewith.
 10. Ina pole pruner of the type including an elongated telescopic handleassembly, a cutting head assembly on one end of said handle assemblyincluding a fixed member operable to be engateD with a limb or the likeand a movable member operable to be moved through a cutting stroke withrelation to the limb engaged by said fixed member, a rope and pulleyassembly operatively connected with said movable member and extending tothe opposite end portion of said handle assembly for effecting movementof said movable member through said cutting stroke in response to amanually effected pull, and spring means for effecting movement of saidmovable member through a return stroke, the improvement in saidtelescopic handle assembly which comprises a first tubular handle part,a second tubular handle part telescopically mounted within said firsthandle part and extending outwardly from one end thereof, and a combinedhandle part securing and rope guiding assembly including securing meansfixedly secured to the exterior periphery of the one end of said firsthandle part and releasably fixedly connected with the exterior peripheryof the portion of said second handle part extending outwardly thereoffor releasably fixedly securing said second handle part with respect tosaid first handle part in any desired position of telescopic adjustment,and guiding means for receiving and guiding the portion of the rope ofsaid rope and pulley assembly extending to the opposite end portion ofsaid handle assembly.
 11. The improvement as defined in claim 10,wherein said rope portion is formed with a knot at a position to engagesaid guide means when said second handle part is moved into a fullyextended position of telescopic adjustment with respect to said firsthandle part providing the operator with indicia of the relativetelescopic position of said handle parts so as to prevent disengagementof said second handle part from said first handle part.
 12. Theimprovement as defined in claim 11, wherein the exterior surface of saidsecond handle part adjacent the portion extending from the one end ofsaid first handle part when said second handle part is in a fullyextended position of telescopic adjustment is provided with colorindicia.
 13. The improvement as defined in claim 10, wherein saidsecuring means includes a pair of cooperating clamping plates, eachcomprising a pair of longitudinally spaced generally semi-cylindricallyshaped central portions, fastener receiving tab portions extending fromone end of each central portion, and an integral portion extending fromthe opposite ends of said central portions, means retaining saidintegral portions in spaced relation on one side of said handle parts,first fastener means carried by one cooperating pair of fastenerreceiving tab portions for releasably fixedly securing the associatedcentral portions in friction tight engagement to said exterior peripheryof said first handle part, and second fastener means carried by theother, cooperating pair of fastener receiving tab portions for effectingthe releasably fixed securement of the associated central portions withsaid exterior periphery of said second handle part.
 14. The improvementas defined in claim 13 wherein said securing means further includes asplit sleeve between the second pair of central portions and saidexterior periphery of said second handle part, said split sleeve havingan annular flange disposed between the first and second pairs of centralportions.
 15. The improvement as defined in claim 15, wherein saidguiding means comprises a pulley journaled between said integralportions.